目的:探讨凋亡机制在凝聚态淀粉样β蛋白(beta-awyloid protein,β)脑内致阿尔茨海默病(Alzheimer disease,D)作用中的意义及何首乌(PMB)对Aβ脑内神经毒性的干预效果.方法:实验于2002-09/2003-02在湘雅医学院解剖学实验室进行.取SD大鼠40只,经Y迷宫测试淘汰4只,6只随机分为生理盐水组,假手术组,模型组和何首乌组.用Aβ1～40微量注射至大鼠右侧海马,建立AD模型,用何首乌进行干预,于不同时间点分别进行电Y迷宫测试,用免疫组化染色法测定Bcl-2阳性神经细胞数的表达,及TUNEL法检测海马神经细胞凋亡的表达.结果:模型组的学习记忆尝试次数为(27.8±7.5)次,海马Bcl-2蛋白表达为(8.71±1.83)个/视野,凋亡细胞为(13.83±3.26)个/视野.何首乌组的学习记忆尝试次数为(15.2±2.9)次,海马Bcl-2蛋白表达为(13.5±2.17)个/视野,凋亡细胞为(9.57±2.16)个/视野,与对照组比差异仍有非常显著性意义(P＜0.01).结论Aβ1～40入海马引起大鼠学习记忆损害,可能与其诱导脑内神经元的凋亡,抑制Bcl-2的表达有关,何首乌对模型鼠的学习记忆障碍具有保护作用,可能与促进Bcl-2的表达而减轻Aβ致AD鼠脑海马神经细胞的凋亡有关.
AIM: To investigate both the significance of apoptosis in the pathogenesis of Alzheimer disease (AD) induced by beta- amyloid(Aβ ) and the effect of tuber fleeceflower root (TFT) on the neurotoxicity of Aβ in rats brain. METHODS:The experiment was performed in the Department of Human Anatomy of Xiangya Medical School from September 2002 to February 2003. 40 SD rats were selected, 4 rats were abandoned by Y maze test, and 36 rats were randomly divided into saline groups, sham operation group and TFT group. The AD rat model was established by infection of Aβ 1- 40 into right hippocampus of rats and was fed with TFT. Learning and memory ability was estimated with Y- electric maze at different time, the expression of positive Bcl- 2 in hippocampus were detected with immunohistochemistry method.The apoptosis neurons were estimated with TUNEL method.RESULTS: The experiment showed that the frequency of attempting learning and memory was 27.8± 7.5,the expression of Bcl- 2 was 8.71± 1.83,and apoptosis neurons was 13.83± 3.26 in model rats. The frequency of attempting learning and memory was 15.2± 2.9, the expression of Bcl- 2 was 13.5± 2.17,apoptosis neurons was 9.57± 2.16 in the TFT group.But there was significant difference as compared with control group (P < 0.01). CONCLUSION:The injection of Aβ 1- 40 into hippocampus of rats can cause the injury of learning and memory abilities,which relates to that the expression of Bcl- 2 is inhibited,which induces apoptosis occurring in model rat. TFT can protect learning and memory abilities,which may relate to inhibit the apoptosis in AD rats hippocampus induced by Aβ through accelerating the expression of Bcl- 2.
Chinese Journal of Clinical Rehabilitation